Electric switch



(No Model.)

B. THOMSON.

ELECTRIC SWITCH.

Patentgd Apr. 13, 1886.

//v mvroe v W'W'TM A TTO/M/Ey WITNESSES:

ELIHU THOMSON, OF LYNN, MASSACHUSETTS.

ELECTRIC SWITCH.

SPECIFICATION forming part of Letters Patent No. 339,714, dated April 13. 1886.

Application filed August 10, 1885.

To all whom it may concern.-

Be it known that I, ELIHU Trroarsou, a eitizen of the United States, and a resident of Lynn, in the county of Essex and State of Massachusetts, have invented certain new and useful Improvements in Electric Switches or Turn-Offs, of which the following is a specification.

The present invention relates to a switch and turn-oft designed more especially for application to incandescent-lamp conductors for breaking and closing the circuit leading to the lamp, and constructed so as to be placed in the ordinary socket or holder of the lamp, which socket or holder may be of any desirable construction.

My invention consistsin certain novel conibinations and details of construction, that will be described in connection with the accompanying drawings, and then designated in the claims.

Figure 1 of the drawings shows the device in section. Fig. 2 is another section of the chief portions of the same. Figs. 3 and 4 show the parts in various positions. Figs. 5 and 6 show the rotary disk-cam. Fig. 7 is a detail of the switch. Figs. 8 and 9 show another detail. Fig. 10 shows the connections when the device is applied to an incandescent lamp.

In Fig. 1, A is a metallic socket, adapted to be screwed upon any fixture, or otherwise attached, and carrying an insulating-block, B, of box-wood or other insulating material. The block B is drilled,so as to furnish a bearing for a spindle or stem carrying a rotary cam, O,and operated bya suitable handle, H, attached to said spindle, and preferably made of insulating material. The cam O is preferably composed, as shown in detail in Figs. 5 and 6, of a circular disk borne on the stem or spindle B, so that the disk may be placed in any position by the operation of the handle H. The disk 0 moves in an opening drilled in the boX-wood, in which opening, just above the disk 0 in Figs. 1 and 2, is located a reciprocatoly rod or block composed of a piston and rod, shaped as shown in Fig. 7, above which piston, and bearing upon it, is a spring, S, for forcing the piston downward upon the cam O. The upper end of the piston-rod bears, when the cam is in the position shown in Figs. 1 and 2, upon Sarial No. 173,957. (No model.)

a small platespring or other suitable contactpiece, T, which is suitably supported, and to which a wire is attached leading to the lamp or circuit supplied, when the device is used as a switch for an incandescent lamp. The connections are as indicated in Fig. 10. A wire, a, is carried directly through to clamping-screws or other connection, from which rises a spring, a, or other connection adapted to make the circuit to one terminal of the lamp. The wire I) is suitably connected to one end of the spring S, or is otherwise put in connection with the cam C or the piston P, the only object being to secure a connection from the piston P to the wire I). The wire or spring connection (1, leading from spring T, is, like a, adapted to make connection with a terminal of the lamp.

Figs. 3 and 4 will exemplify the operation of the switch. Assuming the cam C to be placed as seen in Fig. 3, the spring S is compressed and the piston I lifted, so that the upper end of the rod attached to it passes through the small opening above and bears against the contact-spring T. If the cam (7 be thrown into the position seen in Fig. 4, the connection from the upper end of the rod attached to P with the contact-spring T will be broken by the elastic force of the spring S, exerted on the piston P in a downward direc tion. The piston P is made of about the same size as the disk 0, and has a small depression on its under face, as seen in Fig. 7, which receives the edge of disk 0 when the latter isin a vertical position, as in Fig. The properties thus secured may be briefly stated. On turning the switch from the position seen in Fig. 4 to that shown in Fig. 3 an elastic pressure is met until the edge of the disk Ois made to pass into the small depression on the under side of P. There it remains, contact having been eiiected between T and 1. On turning the switch slightly, so as to turn its edge out of the small depression in P, the spring S in1- mediately comes into play to produce a snapping action and suddenly break the contact between T and I. The switch will not retain an intermediate position of partial contact with the spring T, since the positions shown in Figs. 3 and 4 are the only ones in which there is stability. The switch is capable, however, of being rotated in either direction with 5 cam O at right angles.

like results, and is very simple 'in'its construction. The box-wood or insulating block B need only be drilled so as to permit the passing of the piston P and the spring S, with the Two views of this block are given in Figs. 8 and 90ne a side view, where the dotted lines show the drilling, and the other a bottom view showing the opening for the passing of the piston P and cam G.

What I claim as my invention is 1. In an electric switch or turn-off, the combination, substantially as described,-of a piston, a cylindrical cavity or guide for the fliston, circuit-controlling devices operated by the piston rod or stem, and an actuating carnpiece engaging with the piston, as and for the purpose set forth.

2. In an electric switch or turn-off, the'eonibination of a reciprocating piston, a coiled spring surrounding the piston rod or stem and forming a portion of the electric cireuitto the piston, and a springelectrodawith which the 'tained in'the bore, aspring-contact in line -pistonrod-or sten1engages-for the purpose of closing the electric circuit.

3. In an electric switch, an insulating-block having drilled recesses, as described, for the reception of a spring and spring-pistonpiece, a circular earn turning on an axis transverse to vthe piston, and suitable electric connections, as described.

4. The'eombination of the bored insulatingblock, the piston working in said bore, a spring bearing against the piston and con- With the endofvthe piston-rod, and a rotary cam-piece engaging with the outside face of the piston, as and for the purpose described. Signed at Lynn, in the county of Essex and- -State of Massachusetts, this. 6th day of Au- 4o gust, A. D. 1885.

ELIHU THOMSON.

\Vi tn esses:

E. VVILBUR Bron, J r., J. W. GIBBONY. 

